1. Field of the Invention
The present invention relates to a venting slide fastener stringer for being attached to cushions, pillows, mats, etc. which require venting.
2. Prior Art
There have heretofore been known a variety of venting slide fasteners having vent holes in the fastener stringer tapes. One such slide fastener disclosed in U. S. Pat. No. 4,125,911, patented Nov. 21, 1978, includes a plurality of vent holes punched in stringer tapes of polymer film material as shown in FIG. 4 of the accompanying drawings. When the slide fastener is transversely stretched in response to a lateral pull, the tapes shrink longitudinally and hence get puckered or wavy, which condition causes the interdigitating rows of coupling elements are also to become undulated, thereby making a slider sluggish during the movement therealong to open or close the slide fastener. Garments with such slide fasteners attached are also subjected to puckering under the influence of shrinkage of the tapes. The slide fastener thus stretched is unsightly and has insufficient venting capability due to deformed vent holes. Woven and knitted slide fasteners having vents are shown, for example, in Japanese Utility Model Publications Nos. 51-135709 and 52-24161 published Nov. 2, 1976 and June 1, 1977, respectively.